1. Field of the Invention
This invention relates to horizontal hinged door assemblies such as sidewalk access doors and, in particular, to a gasket system for such door assemblies which comprise a door, a frame surrounding the door, preferably a peripheral channel frame to prevent water and dirt from falling through to the area below covered by the door, and a hinge connecting the door to the frame for rotation about an axis, the gasket system restricting water and dirt from entering a gap between the frame and the edge of the door.
2. Description of Related Art
Horizontal hinged (covers) doors are commonly used for access doors, roof scuttles, automatic fire vents, ceiling access doors, basement doors and for pit, floor and sidewalk doors for access to subterranean locations. While the present description will be directed to pit, floor and sidewalk doors, it will be appreciated that the invention can be used for any such horizontal doors, such as angled bulkhead doors for entering or leaving a basement, where there is a gap between the frame of the door and the edge of the door through which gap water or dirt may enter.
Pit, floor and sidewalk doors are used in a variety of applications for providing access through openings in a concrete slab, wood floor or ceiling, and the like into a pump pit, utility vault, pipe trench, basement, building, etc. Most of the designs for these type doors utilize a channel frame surrounding the door which frame may be connected to a drain. The typical door assembly necessarily has a small gap between the frame and the edge of the door through which water and dirt enters and the drain directs rain water away and the channel restricts dirt from falling through to the covered area below.
The channel frame is usually made of 1/4 metal such as extruded aluminum and is generally a U-shape. The thickness of the frame is usually up to about 1/2 inch, typically 1/4 inch. The dimensions of the U-shape channel may vary widely up to, for example, 5 inch high by 5 inch wide or larger. A typical U-frame is made of 1/4 inch thick extruded aluminum with the frame being about 3.5 inch high by 3 inch wide. The channel frame is made as a continuous extrusion and is cut to the proper length and the four sides of the assembly connected together to form the frame. The frame is positioned at the periphery of the hole opening to which the frame is secured. The top of the outer wall of the channel frame typically has an inward flange extending around the periphery of the channel for strength and to facilitate hinge connection to the door. The height of the inner wall of the frame is generally slightly lower than the outer wall to accommodate the thickness of the door when the door is closed. The door is generally up to about 3/8 inch thick, typically 1/4 inch. When the door is in the closed position, the door rests on the inner wall and the door is flush with the inward flange of the channel frame.
The door covers an opening and there is necessarily a gap due to manufacturing tolerances and operational clearances between the edges of the door and the frame of the door assembly. It is important to keep rain water, dirt and other debris from entering the gap and falling into the frame and/or opening covered by the door assembly. Additionally, dirt and debris can accumulate in the frame or on the frame walls lifting the door above the sidewalk or floor level causing a tripping hazard and possible hinge and door damage.
In a prior art horizontal door assembly shown in FIG. 3, a gasket 43 is used between two confronting surfaces comprising the door 14 and flange 42 of the channel frame 40. The top portion 44 of gasket 43 is compressed between the door 14 and channel flange 42. This type design has certain drawbacks such as a need for continual maintenance of the gasket, the buildup of dirt on the gasket surface and the need for a confronting flange to support the gasket.
Bearing in mind the problems and deficiencies of the prior art, it is one object of the present invention to provide a bendable gasket structure for use with a horizontal door to restrict water, dirt and debris from entering a gap between the door frame and edges of the door.
It is an additional object of the invention to provide a horizontal hinged door assembly having a bendable gasket structure as part of the assembly which gasket restricts water, dirt and debris from entering a gap between the door frame and edges of the door.
It is another object of the invention to provide a horizontal hinged door assembly and/or a frame member used to make horizontal door assemblies which are adapted to utilize a bendable gasket structure of the invention which gasket extends across a gap between the door frame and edges of the door to restrict water, dirt and debris from entering the gap.
Other objects and advantages will be apparent from the following description.